SHADING CORRECTION VALUE CALCULATION DEVICE AND SHADING CORRECTION VALUE CALCULATION METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a correction value for excellently correcting shading relative to a display image even when an obstacle exists between the display image and an imaging device.SOLUTION: A shading correction value calculation method is configured to: obtain a first mapping relationship relative to a shading correction coordinate system from a photographing coordinate system, using a first photographing image acquired by photographing a first display image displayed on a display surface S by means of an image display device by use of an imaging device; eliminate a part corresponding to an object existing between the display surface and the imaging device of the first mapping relationship, and obtain a second mapping relationship; obtain a first gradation value of a part of the shading correction coordinate system by executing a mapping conversion by use of the second mapping relationship relative a second photographing image acquired by photographing a second display image; and obtain, of the shading correction coordinate system, a second gradation value of a part where the gradation value is not obtained by the mapping conversion by means of interpolation processing, and calculate a correction value by use of the first and second gradation values.